In food industry, products containing fats and oils are mainly structured by a functional mixture of high and low melting fats and oils. The provided structuring needs to be controlled because it influences texture, stability, taste, and storage life of a product. The mentioned fats and oils are mainly composed of a mixture of triacylglycerides (TAGs). Since this mixture is not a binary system, the phase behavior is quite complex. A possible distinction of the various fractions in these mixtures is their melting/crystallization temperature. The source of a fat/ oil determines its composition. TAGs from animal fats are high in saturated fatty acid residues (except of e.g. aquatic organisms) while plant based oils are mainly high in unsaturated fatty acid moieties (except of tropical oils e.g. coconut oil). The consumption of unsaturated fatty acids is known to be healthy for humans and, thus, oils containing high concentrations of these are recommended with respect to nutritional aspects. If these unsaturated fatty acids are polyunsaturated they are so called essential fatty acids. Due to processing or the nature of the fats, so called trans fatty acids occur. These are known to have detrimental effects for the health. In fat technology, specific demands are made for different products to achieve the desired properties (e.g. shelf life, health, processing). This requires the functionalization of naturally occurring fats and oils, historically done using fractionation, interesterification, and/or hydrogenation. During fractionation, which is performed batch wise, the fractions are generated due to their distinct melting points. Interesterification exchanges the fatty acid residues at the glycerol backbone of the TAGs randomly. For chemical catalysts, the randomization is complete. Enzymatic catalysts are selective and yield lower reaction rates which makes the resulting composition difficult to predict. The process of hydrogenation is used to achieve different degrees of saturation independent of the raw material. However, during this process, if not conducted completely, trans fatty acids are formed which are known to increase the risk of cardiovascular diseases. The fractionation process is the only functionalization which does not change the molecular structure of the TAGs. Two commonly applied technologies are outlined shortly. The dry fractionation is the cheapest and most applied process but also the least selective and efficient one. The solvent fractionation is more efficient but expensive and the used solvents can cause problems due to hazardous working conditions. A continuous fractionation process would be desirable to decrease production time and costs. Hence, we examined the application of a new emulsion fractionation process which is based on a process applied for margarine production. It aims for a continuous process and specific fractionation of the desired TAGs. The idea is that cold water droplets are injected into a warm oil mixture initiating crystallization of the high melting TAGs at the droplet surface due to local supercooling. These crystals stabilize the water droplet, forming a so called Pickering emulsion. The water droplets stabilized by fat crystals have a higher density than the surrounding liquid oil which makes a separation by centrifugal force possible. This separation step was performed in a lab scale decanter centrifuge achieving a continuous process. Preliminary tests were conducted using a mixture of rapeseed oil and a predetermined amount of fully hydrogenated fat (hardstock) as a model system to know the exact amount of hardstock before and after emulsion fractionation. In addition, experiments with palm oil as a model system were carried out. It was shown that the two processes of crystallization and separation need to be harmonized well to achieve the best separation efficiency. In general, the separation was possible, but the efficiency was very low. Therefore, a better understanding of the influencing parameters used to control the process in the decanter need to be obtained. An accurate knowledge of the phase equilibrium and the kinetics during the continuous process is crucial to establish the window of the apparatus parameters for a successful application. To study the phase equilibrium of the applied materials, an analytical method is required to characterize fats and oils. This method should be reliable, fast, and easily applicable for a large number of experiments. Therefore, the application of the new temperature modulated optical refractometry was evaluated. Fat crystallization is usually investigated by distinct methods to determine phase transitions, the amount of solids, and polymorphic crystal forms. Differential scanning calorimetry is an established method to determine melting and crystallization in fats and oils. Pulsed nuclear magnetic resonance is normally applied to obtain the solid fat content of a material, which is important as a quality parameter and determines the application range of a fat. Powder X ray diffraction is a well known technique to differentiate polymorphic forms in fats which is important for products like chocolate where only one polymorph of cocoa butter delivers the desired product properties. All of these enumerated methods are quite expensive and partially complex in sample handling. A more convenient and cheaper method proofed to be the temperature modulated optical refractometry (TMOR). It determines the refractive index while a temperature modulation is conducted directly on the prism. This yields beside the mean refractive index a thermal volume expansion coefficient a. The method can be carried out in an isothermal and a dynamic way. Both modes are interesting for the application in fat technology and therefore the applicability of TMOR for the investigation of fats and oils was part of this thesis. We found that it is possible to determine phase transitions of aliphatic chain components as well as of more complex systems like fats. Additionally, the device was used to obtain the solid fat content by determining the apparent refractive index of various fats such as coconut oil and applying the lever rule. So far, only the potential to determine polymorphic forms using TMOR was shown. In future work this application of TMOR needs to be further investigated. The applicability of TMOR was shown in this work. In the next step this technique is applied to gain better knowledge of the phase behavior and kinetics so that the process window of the continuous emulsion fractionation can be identified. In summary, both, the new emulsion fractionation technology and the temperature modulated optical refractometry, could be combined. TMOR could be used as analytic method to determine the melting behavior and the solid fat content of the fractionated material. Thereby, important information about the separation efficiency and the resulting TAG fractions would be obtained supporting the optimization of the process design.